This document discusses reactive programming and multi-threading in Android. It introduces the need for threads to avoid UI blocking. It then discusses common threading problems like progress updates and dependencies. It presents solutions from Google like AsyncTask and Handler/Looper as well as Java utilities. It also discusses deferred-promise patterns from libraries like Bolts and RxJava concepts like explicit execution and cancellation. It advocates for RxJava as a way to more easily manage threads and transformations with fewer side effects.

1. 反應式編程起⼿手式-多執⾏行行緒的逆襲
Android Developer - PicCollage
Prada

2. Why we need Thread?
https://en.wikipedia.org/wiki/Thread_(computing)

3. UI Heavy World

4. If you do it wrong.
System will kill you

5. Requirements of
Background Task
https://www.youtube.com/watch?v=IrKoBFLwTN0

6. Threading Problems
report the upload progress to UI

7. Threading Problems
Threads has dependency relationship

8. Threading Problems
Map-Reduce

9. Solution from Google -
AsyncTask

10. Solution from Google -
Handler/Looper

11. Solution from Java
import java.util.concurrent.*
https://www.goodreads.com/book/show/127932.Java_Concurrency_in_Practice
BlockingQueue
Future<T>
Callable<T>
ThreadPoolExecutor
ConcurrentHashMap<K,V>
CountDownLatch

12. Solutions from Google

13. Deferred-Promise Pattern
Bolts-Framework / jDeferred
https://github.com/jdeferred/jdeferred
https://github.com/BoltsFramework

14. We want more!

15. https://youtu.be/XLH2v9deew0?t=4m51s
Asynchronous Ideas
1. Explicit execution
2. Easy thread management
3. Easily transformable
4. As few side effect as possible
5. Cancelation
6. Traffic Control

16. Explicit Execution
Handler RxJava

17. Easy Thread Management
AsyncTask
How many background threads for uploading photos?
RxJava

18. Easily transformable
AsyncTask RxJava

19. As few side effect as possible
<- local storage operation
<- networking operation

20. As few side effect as possible
AsyncTask RxJava

21. Cancelation
https://developer.android.com/reference/android/os/AsyncTask.html#cancel(boolean)
Thread
AsyncTask

22. Cancelation

23. Traffic Control
Normal Case

24. Traffic Control
Worst Case

25. Traffic Control
How to implement it in Java with Threads?
https://www.geeksforgeeks.org/producer-consumer-solution-using-threads-java/

26. Traffic Control in RxJava2

27. Take away
RxJava
Android Framework
Code
Complexity
RxJava
Android Framework
Learning
Curve
if your problem is already complicated

28. Thanks, Question?

29. Reference
Intro to RxJava/ Christina Lee
https://www.youtube.com/watch?v=XLH2v9deew0

30. https://medium.com/@pradabear/deferred-promise-e957bcd235a2
Threading Problems
PicCollage High Resolution Capturing
TODO PicCollage Capturing Video